The present invention relates to gyratory crushers and more specifically to a wear resistant lining for the bottom shell for a gyratory crusher which simplifies manufacturing of the crusher and specifically the placement of a wear resistant lining in the bottom shell of a gyratory crusher.
Gyratory crushers have been known for many years. Large gyratory crushers may include a top shell and a middle shell which together define the crushing chamber. A bottom shell is attached to the middle shell and defines an area below the crushing chamber which receives crushed rock and discharges it from the machine. The crushing chamber is, of course, provided with a wear resistant lining normally consisting of segments of cast manganese steel suitably mounted in the inside of the upper and middle shells. Some crushers, such as those used in crushing less abrasive materials such as certain limestones, do not have the inside of the bottom shell lined because the service is such that there is a minimum of wear of the bottom shell. If wear does occur, repair can be made by welding material onto the inside of the bottom shell, or by the addition of a material such as railroad rails or ultimately, by replacement of the bottom shell. Crushers which are subjected to more severe service, such as those used in mining abrasive materials such as copper and iron ores, often include a bottom shell which is lined with cast manganese steel segments similar to those which line the crushing chamber. The present invention relates to an improved lining for the bottom shell of a gyratory crusher which will replace the use of cast manganese steel liners used prior to the present invention.
Prior practice in lining the bottom shell of a large gyratory crusher consisted of using cast manganese segments with these segments being cast in a generally arcuate shape which is designed to conform to the conical shape of the bottom shell. Each of these segments is cast with a plurality of holes therethrough. In order to install the liners the segment is placed against the inside of the bottom shell, location of the hole in the segment is marked on the bottom shell and then the bottom shell is drilled to receive a fastener, which fastener is used to secure the lining segment to the inside of the bottom shell. The holes in the shell cannot be drilled according to predetermined measurements because the cast holes in the liner segments can shift from their intended position during the casting process. Several disadvantages result from this technique. When the manganese segments are cast and cooled, the actual configuration does not always conform to the intended configuration. The cooled segments do not always have the same radius as the radius of curvature of the bottom shell. This means that the cast segments of improper shape have to be corrected by heating and forming the segment thereby increasing costs. In addition, the holes through the shell are not always located exactly as planned because of operator error. Because prior practice requires drilling from the inside of the shell, it can be a noisy undesirable job for an operator, thus increasing the possibility of error. The entire operation of lining the bottom shell of a large gyratory crusher is a "cut and fit" operation and takes a substantial number of man hours.
In addition to the above problems with prior techniques for lining the bottom shell of a gyratory crusher, the use of cast segments had additional problems. For each bottom shell size, the liner segments will have a different configuration, either radius of curvature or dimensions. This means that for each bottom shell size, there must be a complete set of expensive patterns made to enable casting of the proper size liner segments. These patterns must be maintained as long as it is desired to be able to supply replacement liners.
Each time a bottom shell of a given size is cast, the finished casting will have a slightly different configuration from the previously cast shell made from that pattern. This is inherent in casting techniques. This change in slight configuration means that the lining segment patterns must be adjusted in configuration to each new shell. This increases costs and the amount of time required to construct both the liner segments themselves and the completed, lined shell.
By the present invention, an arrangement has been designed whereby the bottom shell of a gyratory crusher may be lined with a wear resistant steel plate cut to the desired dimensions rather than using cast segments. These plates may be provided with a pair of holes drilled or burned therethrough and the bottom shell itself may be drilled from the outside with the holes located by measurement in a conventional manner rather than by actually placing the lining plates in the bottom shell and then drilling from the inside of the bottom shell.